Massive fail in Cubase? (no, not the crashing bug)

Alrighty then - let me get this straight. Not too long ago the massive bug in Massive that rendered its use as a plugin impossible (crash while loading a preset) was finally fixed. Very nice. However now that I'm no longer deterred from even trying to use this fine-looking instrument, it appears that what is still not fixed is something even more massive:

using Cubase 5, I'm getting:

- massive crackling both during playback and export when using multiprocessing
- silence from the Massive track when doing a non-realtime export
- normal playback and output when using non-multicore realtime export

I know PLAY had a similar (but not the same) issue that was attributed to Steinberg rather than East West a while ago, but that was fixed something like 5-7 months ago, so I won't jump on NI just yet; however, if this kind of behavior is attributable to Massive, then I guess we're back in the stoneage and I'll simply shelve the suite once more. My projects are rather large and reverting to single-core playback is pretty much out of the question even if I could generally manage realtime export.

Since Googling isn't turning up any good results, can anyone please verify that this indeed is related to Massive and whether this kind of behavior also occurs in Cubase 6, which I haven't yet had the privilege or the resources to acquire?